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July 29, 2009

Economist's View - 5 new articles

"How Wars, Plagues, and Urban Disease Propelled Europe's Rise to Riches"

[Note: Travel day today, so I am letting things that are posted do most of the talking. I'll add what I can along the way. Update: Off to a great start - left my iPhone at the last airport ... grrr. Update: Sitting in Detroit airport, hungry, and just dropped my sandwich on the floor. I really want to eat it anyway, but won't. ... grrr. Update: I made it to Ithaca, someone found my phone and turned it in to lost and found, and I got another sandwich. Plus, amazingly, the shuttle to the hotel was waiting when I walked out to get a taxi. Yeah! Now the only problem is that I usually go to sleep pretty late - 3 a.m. is not unusual - and that's about when I have to get up given the time change. Hmmm. That won't help my talk. ... back to grrr.]

"This column explains why Europe's rise to riches in the early modern period owed much to exceptionally bellicose international politics, urban overcrowding, and frequent epidemics."

Cruel windfall: How wars, plagues, and urban disease propelled Europe's rise to riches, by Nico Voigtländer and Hans-Joachim Voth, Vox EU: In a pre-modern economy, incomes typically stagnate in the long run. Malthusian regimes are characterised by strongly declining marginal returns to labour. One-off improvements in technology can temporarily raise output per head. The additional income is spent on more (surviving) children, and population grows. As a result, output per head declines, and eventually labour productivity returns to its previous level. That is why, in HG Wells' phrase, earlier generations "spent the great gifts of science as rapidly as it got them in a mere insensate multiplication of the common life" (Wells, 1905).

How could an economy ever escape from this trap? To learn more about this question, we should look more closely at the continent that managed to overcome stagnation first. Long before growth accelerated for good in most countries, a first divergence occurred. European incomes by 1700 exceeded those in the rest of the world by a large margin. We explain the emergence of this income gap by a number of uniquely European features – an unusually high frequency of war, particularly unhealthy cities, and numerous deadly disease outbreaks.

The puzzle: The first divergence in worldwide incomes

European incomes by 1700 were markedly higher than they had been in 1500. According to the figures compiled by Angus Maddison (2001), all European countries including Mediterranean ones saw income growth of 35% to 180%. Within Europe, the northwest did markedly better than the rest. English and Dutch real wages surged during the early modern period.

How exceptional was this performance? Pomeranz (2000) claimed that the Yangtze Delta in China was just as productive as England. Detailed work on output statistics suggests that his claims must be rejected. While real wages in terms of grain were some 15-170% higher in England, English silver wages exceeded those of China by 120% to 550%. Since grain was effectively an untraded good internationally before 1800, the proper standard of comparison is the silver wage. Estimates for India suggest a similar gap vis-à-vis Europe (Broadberry and Dasgupta, 2006).

Urbanisation figures support this conclusion. They serve as a good proxy since people in towns need to be fed by farmers in the countryside. This requires a surplus of food production, which implies high labour productivity. Since agriculture is the largest single sector in all pre-modern economies, a productive agricultural sector is equivalent to high per capita output overall. Figure 1 compares European and Chinese urbanisation rates after the year 1000 AD. Independent of the series used, European rates increase rapidly during the early modern period. Our preferred measure – the DeVries series – increases from 5% to nearly 10% between 1500 and 1800. The contrast with China is striking. There, urbanisation stagnated near the 3% mark.

Figure 1. Europe versus China urbanisation rates, 1000-1800


In a Malthusian world, a divergence in living standards should be puzzling. Income gains from one-off inventions should have been temporary. Even ongoing productivity gains cannot account for the "first divergence" – TFP growth probably did not exceed 0.2%, and cannot explain the marked rise in output per capita.

The answer: Rising death rates and lower fertility

In a Malthusian world, incomes can increase if birth rates fall or death rates increase (Clark, 2007). Figure 2 illustrates the basic logic. Incomes are pinned down by the intersection of birth and death schedules (denoted b and d). The initial equilibrium is E0. If death rates shift out, to d', incomes rise to the new equilibrium Ed1. Similarly, lower birth rates at any given level of income will lead to higher per capita incomes. In combination, shifts of the birth and death schedules to b' and d' will move the economy to equilibrium point E2.

Figure 2. Birth and death rates, and equilibrium per capita income


We argue that there were three factors – which we call the "Three Horsemen of Riches" – that shifted Europe's death schedule outwards: wars, epidemics, and urban disease. Wars were unusually frequent. Epidemics were common, with devastating consequences. Finally, cities were particularly unhealthy, with death rates there exceeding birth rates by a large margin – without in-migration, European cities before 1850 would have disappeared.

Figure 3 shows the percentage of the European population affected by wars (defined as those living in areas where wars were fought). It rises from a little over 10% to 60% by the late seventeenth century. Tilly (1992) estimated that, on average, there was a war being fought somewhere in nine out of every ten years in Europe in the early modern period.

Political fragmentation combined with religious strife after 1500 to form a potent mix that produced almost constant military conflict. While the fighting itself only killed few people, armies marching across Europe spread diseases. It has been estimated that a single army of 6,000 men, dispatched from La Rochelle to fight in the Mantuan war, killed up to a million people by spreading the plague (Landers, 2003).

Figure 3. Share of European population in war zones


European cities were much unhealthier than their Far Eastern counterparts. They probably had death rates that exceeded rural ones by 50%. In China, the rates were broadly the same in urban and rural areas. The reason has to do with differences in diets, urban densities, and sanitation:

  • Europeans ate more meat, and hence kept more animals in close proximity,
  • European cities were protected by walls due to frequent wars, which could not be moved without major expense, and
  • Europeans dumped their chamber pots out of their windows, while human refuse was collected in Chinese cities and used as fertiliser in the countryside.

Epidemics were also frequent. The plague did not disappear from Europe after 1348. Indeed, plague outbreaks continued until the 1720s, peaking at over 700 per decade in the early 17th century. In addition to wars, epidemics were spread by trade. The last outbreak of the plague in Western Europe occurred in Marseille in 1720; a merchant vessel from the Levant spread the disease, causing 100,000 men and women to perish. Since Europe has much greater variety in terms of geography and climate than China, disease pools remained largely separate. When they became increasingly connected as a result of more trade and wars, mortality spiked.

Triggering European "exceptionalism"

In combination, the "Three Horsemen" – war, urbanisation, and trade-driven disease – probably raised death rates by one percentage point by 1700. Once death rates were higher, incomes could remain at an elevated level even in a Malthusian world. The crucial question then becomes why Europe developed such a particular set of factors driving up mortality.

We argue that the Great Plague of 1348-50 was the key. Between one third and one half of Europeans died. With land-labour ratios now higher, per capita output and wages surged. Since population losses were massive, they could not be compensated quickly. For a few generations, the old continent experienced a "golden age of labour". British real wages only recovered their 1450s peak in the age of Queen Victoria (Phelps-Brown and Hopkins, 1981).

Temporarily higher wages changed the nature of demand. Despite having more children, people had more income than necessary for mere subsistence – population losses were too large to be absorbed entirely by the demographic response. Some of the surplus income was spent on manufactured goods. These goods were mainly produced in cities. Thus, urban centres grew in size. Higher incomes also generated more trade. Finally, the increasing number and wealth of cities expanded the size of the monetised sector of the economy. The wealth of cities could be taxed or seized by rulers. Resources available for fighting wars increased – war was effectively a superior good for early modern princes. Therefore, as per capita incomes increased, death rates rose in parallel. This generates a potential for multiple equilibria. Figure 4 illustrates the mechanism. The death rate increases over some part of the income range, which maps into urbanisation rates. Starting at E0, a sufficiently large shock will move the economy to point EH, where population is again stable.

Figure 4. Equilibria with "Horsemen effect"


In the discussion paper, we calibrate our model. The effect of higher mortality on living standards is large. We find that we can account for more than half of Europe's precocious rise in per capita incomes until 1700.


To raise incomes in a Malthusian setting, death rates have to rise or fertility rates have to decline. We argue that a number of uniquely European characteristics – the fragmented nature of politics, unhealthy cities, and a geographically heterogeneous terrain – interacted with the shock of the 1348 plague to create exceptionally high mortality rates. These underpinned a high level of per capita income, but the riches were bought at a high cost in terms of human lives.

At the same time, there are good reasons to think that it is not entirely accidental that the countries (and regions) that were ahead in per capita income terms in 1700 were also the first to industrialise. How the world could escape the Malthusian trap at all has become a matter of intense interest to economists in recent years (Galor and Weil, 2000, Jones, 2001, Hansen and Prescott, 2002). In a related paper, we calibrate a simple growth model to show why high per capita income at an early stage may have been key for Europe's rise after 1800 (Voigtländer and Voth, 2006).

In the "Three Horsemen of Riches", we ask how Europe got to be rich in the first place. Our answer is best summarised by the smuggler Harry Lime, played by Orson Welles in the 1948 classic "The Third Man":

"In Italy, for thirty years under the Borgias, they had warfare, terror, murder, bloodshed, but they produced Michelangelo, Leonardo da Vinci and the Renaissance. In Switzerland, they had brotherly love; they had 500 years of democracy and peace – and what did that produce? The cuckoo clock."

We argue that a similar logic held in economic terms before the Industrial Revolution. Europe's exceptional rise to early riches owed much to forces of destruction – war, aided by frequent disease outbreaks and deadly cities.


Bairoch, P., J. Batou, and P. Chèvre (1988). La Population des villes Europeennes de 800 à 1850: Banque de Données et Analyse Sommaire des Résultats. Geneva: Centre d'histoire economique Internationale de l'Université de Genève, Libraire Droz.

Broadberry, S. and B. Gupta (2006). "The Early Modern Great Divergence: Wages, Prices and Economic Development in Europe and Asia, 1500-1800". Economic History Review 59, 2–31.

Chow, G. C. and A. Lin (1971). "Best Linear Unbiased Interpolation, Distribution, and Extrapolation of Time Series by Related Series". Review of Economics and Statistics 53(4), 372–375.

Clark, G. (2007). A Farewell to Alms: A Brief Economic History of the World. Princeton: Princeton University Press.

de Vries, J. (1984). European Urbanization 1500-1800. London: Methuen.

Galor, O. and D. N. Weil (2000). "Population, Technology and Growth: From the Malthusian Regime to the Demographic Transition and Beyond". American Economic Review 90(4), 806–828.

Hansen, G. and E. Prescott (2002). "Malthus to Solow". American Economic Review 92(4), 1205–1217.

Jones, C. I. (2001). "Was an Industrial Revolution Inevitable? Economic Growth Over the Very Long Run". Advances in Macroeconomics 1(2). Article 1.

Landers, J. (2003). The Field and the Forge: Population, Production, and Power in the Pre-Industrial West. New York: Oxford University Press.

Maddison, A. (2001). The World Economy. A Millennial Perspective. Paris: OECD.

McEvedy, C. and R. Jones (1978). Atlas of World Population History, Facts on File. New York.

Pomeranz, K. (2000). The Great Divergence: China, Europe, and the Making of the Modern World Economy. Princeton, N.J.: Princeton University Press.

Phelps-Brown, H. and S. V. Hopkins (1981). A Perspective of Wages and Prices. London. New York, Methuen.

Tilly, C. (1992). Coercion, Capital, and European States, AD 990-1992. Oxford: Blackwells.

Voigtländer, N. and H.-J. Voth (2008). "The Three Horsemen of Growth: Plague, War and Urbanization in Early Modern Europe". CEPR discussion paper 7275.

Voigtländer, N. and H.-J. Voth (2006). "Why England? Demographic Factors, Structural Change and Physical Capital Accumulation during the Industrial Revolution". Journal of Economic Growth 11, 319–361.

Wells, H. G. (1905). A Modern Utopia.

"Why had Nobody Noticed that the Credit Crunch Was on its Way?"

A letter to the Queen attempting to explain why economists missed the financial crisis:

Her Majesty The Queen Buckingham Palace London SW1A 1AA


When Your Majesty visited the London School of Economics last November, you quite rightly asked: why had nobody noticed that the credit crunch was on its way? The British Academy convened a forum on 17 June 2009 to debate your question... This letter summarises the views of the participants ... and we hope that it offers an answer to your question.

Many people did foresee the crisis. However, the exact form that it would take and the timing of its onset and ferocity were foreseen by nobody. ...

There were many warnings about imbalances in financial markets... But the difficulty was seeing the risk to the system as a whole rather than to any specific financial instrument or loan. Risk calculations were most often confined to slices of financial activity, using some of the best mathematical minds in our country and abroad. But they frequently lost sight of the bigger picture.

Many were also concerned about imbalances in the global economy ... known as the 'global savings glut'. ... This ... fuelled the increase in house prices both here and in the USA. There were many who warned of the dangers of this.

But against those who warned, most were convinced that ... the financial wizards had found new and clever ways of managing risks. Indeed, some claimed to have so dispersed them through an array of novel financial instruments that they had virtually removed them. It is difficult to recall a greater example of wishful thinking combined with hubris. There was a firm belief, too, that financial markets had changed. ... A generation of bankers and financiers deceived themselves and those who thought that they were the pace-making engineers of advanced economies.

All this exposed the difficulties of slowing the progression of such developments in the presence of a general 'feel-good' factor. Households benefited from low unemployment, cheap consumer goods and ready credit. Businesses benefited from lower borrowing costs. Bankers were earning bumper bonuses... The government benefited from high tax revenues... This was bound to create a psychology of denial. It was a cycle fuelled, in significant measure, ... by delusion.

Among the authorities charged with managing these risks, there were difficulties too. ... General pressure was for more lax regulation – a light touch. ...

There was a broad consensus that it was better to deal with the aftermath of bubbles ... than to try to head them off in advance. Credence was given to this view by the experience, especially in the USA ... when a recession was more or less avoided after the 'dot com' bubble burst. This fuelled the view that we could bail out the economy after the event.

Inflation remained low and created no warning sign of an economy that was overheating. ... But this meant that interest rates were low by historical standards. And some said that policy was therefore not sufficiently geared towards heading off ... risks. ... But on the whole, the prevailing view was that monetary policy was best used to prevent inflation and not to control wider imbalances in the economy.

So where was the problem? Everyone seemed to be doing their own job properly... And according to standard measures of success, they were often doing it well. The failure was to see how collectively this added up to a series of interconnected imbalances over which no single authority had jurisdiction. This, combined with the psychology of herding and the mantra of financial and policy gurus, lead to a dangerous recipe. Individual risks may rightly have been viewed as small, but the risk to the system as a whole was vast.

So in summary, Your Majesty, the failure..., while it had many causes, was principally a failure of the collective imagination of many bright people, both in this country and internationally, to understand the risks to the system as a whole. ...

We have the honour to remain, Madam, Your Majesty's most humble and obedient servants

Professor Tim Besley, FBA Professor Peter Hennessy, FBA

[See also At your own risk and Economists were beholden to the long boom.]

Exchequer Tallies

The "first experiment with derivative financial instruments":

Theory of Games and Economic Misbehavior, by George Dyson, Edge: ...There are numerous precedents for [the derivatives now haunting us].

As early as the twelfth century it was realized that money ... can be made to exist in more than one place at a single time. An early embodiment of this principle, preceding the Bank of England by more than five hundred years, were Exchequer tallies — notched wooden sticks issued as receipts for money deposited with the Exchequer for the use of the king. "As a financial instrument and evidence it was at once adaptable, light in weight and small in size, easy to understand and practically incapable of fraud," wrote Hilary Jenkinson in 1911. ...

A precise description was given by Alfred Smee... "The tally-sticks were made of hazel, willow, or alder wood, differing in length according to the sum required to be expressed upon them. They were roughly squared, and one end was pointed; and on two sides of that extremity, the proper notches, showing the sum for which the tally was a receipt, were cut across the wood." 11

On the other two sides of the tally were written, in ink and in duplicate, the name of the party paying the money, the account for which it was paid, and the date of payment. The tally was then split in two, with each half retaining the notched information as well as one copy of the inscription. "One piece was then given to the party who had paid the money, for which it was a sufficient discharge," Smee continues, "and the other was preserved in the Exchequer. Rude and simple as was this very ancient method of keeping accounts, it appears to have been completely effectual in preventing both fraud and forgery for a space of seven hundred years. No two sticks could be found so exactly similar ... when split in the coarse manner of cutting tallies; and certainly no alteration of the ... notches and inscription could remain undiscovered when the two parts were again brought together. ..." 12

Exchequer tallies were ordered replaced in 1782 by an "indented cheque receipt," but the Act of Parliament (23 Geo. 3, c. 82) thereby abolishing "several useless, expensive and unnecessary offices" was to take effect only on the death of the incumbent who, being "vigorous," continued to cut tallies until 1826. "After the further statute of 4 and 5 William IV the destruction of the official collection of old tallies was ordered," noted Hilary Jenkinson. "The imprudent zeal with which this order was carried out caused the fire which destroyed the Houses of Parliament in 1834." 13

The notches were of various sizes and shapes corresponding to the tallied amount: a 1.5-inch notch for £1000, a 1-inch notch for £100, a half-inch notch for £20, with smaller notches indicating pounds, shillings, and pence, down to a halfpenny, indicated by a pierced dot. The code was similar to bar-coding... And the self-authentication achieved by distributing the information across two halves of a unique piece of wood is analogous to the way large numbers, split into two prime factors, are used to authenticate digital financial instruments today. Money was being duplicated: the King gathered real gold and silver into the treasury through the Exchequer, yet the tally given in return allowed the holder to enter into trade, manufacturing, or other ventures, producing real wealth with nothing more than a wooden stick.

Until the Restoration tallies did not bear interest, but in 1660, on the accession of Charles II, interest-bearing tallies were introduced. They were accompanied by written orders of loan which, being made assignable by endorsement, became the first negotiable interest-bearing securities in the English-speaking world. Under pressure of spiraling government expenditures the order of loan was soon joined by an instrument called an order of the Exchequer, drawn not against actual holdings but against future revenue and sold at a discount to the private goldsmith bankers whose hard currency was needed to prop things up. In January 1672, unable to meet its obligations, Charles II declared a stop on the Exchequer. At the expense of the private bankers, this first experiment with derivative financial instruments came to an end. ...

Wealth Inequality

Daniel Little on wealth inequality:

Wealth inequality, by Daniel Little: When we talk about inequality in the United States, we usually have a couple of different things in mind. We think immediately of income inequality. Inequalities of important life outcomes come to mind (health, housing, education), and, of course, we think of the inequalities of opportunity that are created by a group's social location (race, urban poverty, gender). But a fundamental form of inequality in our society is a factor that influences each of these: inequalities of wealth across social groups. Wealth refers to the ownership of property, tangible and intangible: for example, real estate, stocks and bonds, savings accounts, businesses, factories, mines, forests, and natural resources. Two facts are particularly important when it comes to wealth: first, that wealth is in general very unevenly distributed in the United States, and second, that there are very striking inequalities when we look at the average wealth of major social groups.

Edward Wolff has written quite a bit about the facts and causes of wealth inequality in the United States. A recent book, Top Heavy: The Increasing Inequality of Wealth in America and What Can Be Done About It, Second Edition, is particularly timely; also of interest is Assets for the Poor: The Benefits of Spreading Asset Ownership. Wolff summarizes his conclusion in these stark terms:

The gap between haves and have-nots is greater now--at the start of the twenty-first century--than at anytime since 1929. The sharp increase in inequality since the late 1970s has made wealth distribution in the United States more unequal than it is in what used to be perceived as the class-ridden societies of northwestern Europe. ... The number of households worth $1,000,000 or more grew by almost 60 percent; the number worth $10,000,000 or more almost quadrupled. (2-3)

The international comparison of wealth inequality is particularly interesting. Wolff provides a chart of the share of marketable wealth held by the top percentile in the UK, Sweden, and the US, from 1920 to 1992. The graph is striking. Sweden starts off in 1920 with 40% of wealth in the hands of the top one percent, and falls fairly steadily to just under 20% in 1992. UK starts at a staggering 60% (!) in the hands of the top 1 percent in 1920, and again, falls steadily to a 1992 level of just over 20%. The US shows a different pattern. It starts at 35% in 1920 (lowest of all three countries); then rises and falls slowly around the 30% level. The US then begins a downward trend in the mid-1960s, falling to a low of 20% in the 1970s; and then, during the Reagan years and following, the percent of wealth rises to roughly 35%. So we are roughly back to where we were in 1920 when it comes to wealth inequalities in the United States, by this measure.

Why does this kind of inequality matter?

Partly because significant inequalities of wealth have important implications for such things as the relative political power of various groups; the opportunities that groups have within and across generations; and the relative security that various individuals and groups have when faced with economic adversity. People who own little or nothing have little to fall back on when they lose a job, face a serious illness, or move into retirement. People who have a lot of wealth, by contrast, are able to exercise a disproportionate amount of political influence; they are able to ensure that their children are well educated and well prepared for careers; and they have substantial buffers when times are hard.

Wolff offers a good summary of the empirical data about wealth inequalities in the United States. But we'd also like to know something about the mechanisms through which this concentration of wealth occurs. Several mechanisms come readily to mind. People who have wealth have an advantage in gathering the information necessary to increase their wealth; they have networks of other wealth holders who can improve their access to opportunities for wealth acquisition; they have advantages in gaining advanced professional and graduate training that increase their likelihood of assuming high positions in wealth-creating enterprises; and they can afford to include high-risk, high-gain strategies in their investment portfolios. So there is a fairly obvious sense in which wealth begets wealth.

But part of this system of inequality of wealth ownership in the United States has to do with something else: the workings of race. The National Urban League publishes an annual report on "The State of Black America." One of the measures that it tracks is the "wealth gap" -- the differential in home ownership between black and white adults. This gap continues to persist, and many leaders in the effort towards achieving equality of opportunity across racial groups point to this structural inequality as a key factor. Here is a very good study on home ownership trends for black and white adults done by George Masnick at the Joint Center for Housing Studies at Harvard (2001). The gap in the 1990s fluctuated around 28% -- so, for example, in 1988-1998 about 52% of blacks between 45 and 54 were home owners, whereas about 80% of non-Hispanic whites in this age group were homeowners (figure 5). Historical practices of mortgage discrimination against specific neighborhoods influence home ownership rates, as do other business practices associated with the workings of residential segregation. Some of these mechanisms are illustrated in Kevin Kruse and Thomas Sugrue's The New Suburban History, and Kevin Boyle's Arc of Justice: A Saga of Race, Civil Rights, and Murder in the Jazz Age provides an absorbing account of how challenging "home ownership" was for professional black families in Detroit in the 1920s.

So what are the remedies for the very high level of wealth inequality that is found in the United States? Wolff focuses on tax remedies, and certainly these need to be a part of the story. But remedying the social obstacles that exist for disadvantaged families to gain property -- most fundamentally, disadvantages that derive from the educational opportunities that are offered to children and young people in inner-city neighborhoods -- is crucial as well. It seems axiomatic that the greatest enhancement that can be offered to a young person is a good education; and this is true in the question of wealth acquisition no less than the acquisition of other socially desirable things.

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